Determination of Regulatory Review Period for Purposes of Patent Extension; ZosynRegister

DEPARTMENT OF HEALTH AND HUMAN SERVICES

[Docket No. 94E-0071]

Determination of Regulatory Review Period for Purposes of Patent

Extension; Zosyn

AGENCY: Food and Drug Administration, HHS.

ACTION: Notice.

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SUMMARY: The Food and Drug Administration (FDA) has determined the

regulatory review period for Zosyn and is publishing this

notice of that determination as required by law. FDA has made the

determination because of the submission of an application to the

Commissioner of Patents and Trademarks, Department of Commerce, for the

extension of a patent which claims that human drug product.

ADDRESSES: Written comments and petitions should be directed to the

Dockets Management Branch (HFA-305), Food and Drug Administration, rm.

1-23, 12420 Parklawn Dr., Rockville, MD 20857.

FOR FURTHER INFORMATION CONTACT: Brian J. Malkin, Office of Health

Affairs (HFY-20), Food and Drug Administration, 5600 Fishers Lane,

Rockville, MD 20857, 301-443-1382.

SUPPLEMENTARY INFORMATION: The Drug Price Competition and Patent Term

Restoration Act of 1984 (Pub. L. 98-417) and the Generic Animal Drug

and Patent Term Restoration Act (Pub. L. 100-670) generally provide

that a patent may be extended for a period of up to 5 years so long as

the patented item (human drug product, animal drug product, medical

device, food additive, or color additive) was subject to regulatory

review by FDA before the item was marketed. Under these acts, a

product's regulatory review period forms the basis for determining the

amount of extension an applicant may receive.

A regulatory review period consists of two periods of time: a

testing phase and an approval phase. For human drug products, the

testing phase begins when the exemption to permit the clinical

investigations of the drug becomes effective and runs until the

approval phase begins. The approval phase starts with the initial

submission of an application to market the human drug product and

continues until FDA grants permission to market the drug product.

Although only a portion of a regulatory review period may count toward

the actual amount of extension that the Commissioner of Patents and

Trademarks may award (for example, half the testing phase must be

subtracted as well as any time that may have occurred before the patent

was issued), FDA's determination of the length of a regulatory review

period for a human drug product will include all of the testing phase

and approval phase as specified in 35 U.S.C. 156(g)(1)(B).

FDA recently approved for marketing the human drug product

Zosyn (tazobactam sodium and piperacillin sodium).

Zosyn is indicated as for the treatment of patients with

moderate to severe infections caused by piperacillin resistant,

piperacillin/tazobactam susceptible, -lactamase producing

strains of the designated microorganisms in certain specified

conditions. Subsequent to this approval, the Patent and Trademark

Office received a patent term restoration application for

Zosyn (U.S. Patent No. 4,562,073) from Taiho Pharmaceutical

Co., Ltd., and the Patent and Trademark Office requested FDA's

assistance in determining this patent's eligibility for patent term

restoration. In a letter dated April 19, 1994, FDA advised the Patent

and Trademark Office that this human drug product had undergone a

regulatory review period and that the approval of Zosyn

represented the first permitted commercial marketing or use of the

product. Shortly thereafter, the Patent and Trademark Office requested

that FDA determine the product's regulatory review period.

FDA has determined that the applicable regulatory review period for

Zosyn is 1,819 days. Of this time, 1,038 days occurred during

the testing phase of the regulatory review period, while 781 days

occurred during the approval phase. These periods of time were derived

from the following dates:

1. The date an exemption under section 505(i) of the Federal Food,

Drug, and Cosmetic Act became effective: October 31, 1988. The

applicant claims July 10, 1988, as the date the investigational new

drug application (IND) for Zosyn (IND 31,705) became

effective. However, IND 31,705 was received on June 14, 1988, and it

was placed on clinical hold on July 1, 1988. It was removed from

clinical hold on October 31, 1988, making the IND effective date

October 31, 1988.

2. The date the application was initially submitted with respect to

the human drug product under section 507 of the Federal Food, Drug, and

Cosmetic Act: September 3, 1991. The applicant claims August 30, 1991,

as the date the new drug application (NDA) for Zosyn (NDA 50-

684) was initially submitted. However, FDA records indicate that NDA

50-684 was submitted on September 3, 1991.

3. The date the application was approved: October 22, 1993. FDA has

verified the applicant's claim that NDA 50-684 was approved on October

22, 1993.

This determination of the regulatory review period establishes the

maximum potential length of a patent extension. However, the U.S.

Patent and Trademark Office applies several statutory limitations in

its calculations of the actual period for patent extension. In its

application for patent extension, this applicant seeks 1,358 days of

patent term extension.

Anyone with knowledge that any of the dates as published is

incorrect may, on or before October 31, 1994, submit to the Dockets

Management Branch (address above) written comments and ask for a

redetermination. Furthermore, any interested person may petition FDA,

on or before February 27, 1995, for a determination regarding whether

the applicant for extension acted with due diligence during the

regulatory review period. To meet its burden, the petition must contain

sufficient facts to merit an FDA investigation. (See H. Rept. 857, part

1, 98th Cong., 2d sess., pp. 41-42, 1984.) Petitions should be in the

format specified in 21 CFR 10.30.

Comments and petitions should be submitted to the Dockets

Management Branch (address above) in three copies (except that

individuals may submit single copies) and identified with the docket

number found in brackets in the heading of this document. Comments and

petitions may be seen in the Dockets Management Branch between 9 a.m.

and 4 p.m., Monday through Friday.

Dated: August 16, 1994.

Stuart L. Nightingale,

Associate Commissioner for Health Affairs.

[FR Doc. 94-21286 Filed 8-29-94; 8:45 am]

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